The Green Box generates three tones, which are suspiciously the same as three particular Blue Box Tones. The function of these tones were to command a payphone to return the caller's money, collect the money from a holding chamber into the main coin box, or to have the switch call the phone back. The idea was that an operator would have some powers when dealing with payphone callers.


These are described by text files as part of ACTS but really they are just selected MF blue box tones. Every blue box is also a green box.


Although the files written about the green box are credible, the whole ACTS system is on its way out and the green box tones themselves were scrapped with inband signaling anyway (operators today DO NOT have blue boxes at their fingertips). So green box tones no longer work.


There is one possible exception: Certain models of Protel COCOT are said to respond to a certain SF (single frequency) tone by returning the deposited coins. Although the tone can probably be determined from experimentation (hint: it was discovered by accident within the electronic melody played to the called by the General Electric "Cordless Answering System" while the tape is seeking...) the discoverer of this New Green Box has not divulged its exact frequency. To my knowledge no one has duplicated this.

Plausibility

It was a real box but it was far more talked about than actually used, so it's really now more the stuff of legend than anything else.

Obsolescence

Totally obsolete. Correct me on this one if I'm wrong. I have heard from many different sources that it doesn't work, and I have never heard of anyone using one with success.

Skill

To build the tone generator would have taken some doing, but taped or PC-Generated tones are a total no-brainer.

Risks

Don't try it. The phone company may have MF detectors set up and think you're trying to blue box.

Description from The Fixers Box Review @ ArtofHacking.com